Relation between new 'field radius' w/sub infinity / and Petermann II field radius w/sub d/ in single-mode fibres with arbitrary refractive index profile

摘要

The author reports a new simple relation between the 'field radius' w/sub infinity / and the Petermann II field radius w/sub d/. This relation is derived from the scalar wave equation and holds for single mode fibres with arbitrary radial refractive index profiles. With this new relation the spectral behaviour of w/sub infinity / can be predicted from the value of w/sub infinity / at one wavelength (e.g. 1.5 mu m) and the spectral behaviour of w/sub d/.